CD Player Modification

[Monjul]

Hi. I have a Cambridge 640C V2 that I'm considring having modified for better performance. My question is as to whether or not these mods are worth the price. The mod I'm considering includes "dual HexFred power supply, upgraded caps, additional filter and bypass components, Burr-Brown Select op amps and additional vibration damping for $175.

Any advice would be appreciated. Thanks.

[SY]

The first question to ask is to yourself, what is the performance problem I'm trying to remediate? The second question to ask is to the fellow selling the mod: how does your modification address the problem? Then the third question, also to the modifier, is do you have data to back that up?

If you don't get satisfactory answers to the second two questions, smile, back away, then run like hell.

[Monjul]

I'm waiting for an email reply from the vendor describing the sonic benefits of the mods. My major complaint with this CD player includes a slightly bleached, slightly harsh quality to the sound and a tendancy to sound confused with dynamic, large scale recordings. Images tend to sound bunched together when things get complicated.

[SY]

Sounds more like amp or speaker issues; your description matches my impressions when I listen to SET amps or speakers experiencing dynamic compression.

I would absolutely NOT trust a vendor to accurately tell you the "sonic benefits." That's far too easy to make up. Does the mod decrease noise? Great, let's see the data. Decrease distortion? Sure, ditto. If I'm asking for $175 of your money and the best I can do is tell you, "The highs will be more liquid and the soundstage will show increased refulgence," or something like that, I'm likely ripping you off.

Of course, if your vendor can provide controlled listening test data, great, but I've never seen any one-off modifier who did so.

[abraxalito]

Originally Posted by Monjul

My major complaint with this CD player includes a slightly bleached, slightly harsh quality to the sound and a tendancy to sound confused with dynamic, large scale recordings. Images tend to sound bunched together when things get complicated.

Sounds familiar - my experience of cheap CD/DVD players. Its normally grounding/decoupling (i.e. poor noise control). The mods list sounds highly fashionable and simple to implement but largely ineffective at making the kinds of changes required. Do you have schematics and layout diagrams for the player in question? If so I might be able to make suggestions for what you can do yourself to save that $175. Its much more fun too.

[Monjul]

Originally Posted by SY

Sounds more like amp or speaker issues; your description matches my impressions when I listen to SET amps or speakers experiencing dynamic compression.

I would absolutely NOT trust a vendor to accurately tell you the "sonic benefits." That's far too easy to make up. Does the mod decrease noise? Great, let's see the data. Decrease distortion? Sure, ditto. If I'm asking for $175 of your money and the best I can do is tell you, "The highs will be more liquid and the soundstage will show increased refulgence," or something like that, I'm likely ripping you off.

Of course, if your vendor can provide controlled listening test data, great, but I've never seen any one-off modifier who did so.

Previously, this particular vendor described the sound of an upgraded Arc SP9 MKII prior to me sending it in for modification. His description is exactly what I hear in the upgraded preamp so I don't see any reason to doubt his credibility. In fact, he steered me away from certain component changes I requested that he thought were a waste of money.

[Monjul]

Originally Posted by abraxalito

Sounds familiar - my experience of cheap CD/DVD players. Its normally grounding/decoupling (i.e. poor noise control). The mods list sounds highly fashionable and simple to implement but largely ineffective at making the kinds of changes required. Do you have schematics and layout diagrams for the player in question? If so I might be able to make suggestions for what you can do yourself to save that $175. Its much more fun too.

I don't have a schematic unfortunately but from what I understand the Cambridge CD players in general skimp on the PS components and op-amps resulting in a bleached, slightly harsh sound that many complain about. Many of these people comment that the mods to the PS and op-amps effectively correct these issues.

Why do you think the quoted mods wouldn't help resolve these issues?

[abraxalito]

Well they tend to be band-aids rather than what's needed - surgery. Upgrading power supplies in my view is a way to quieten down grounds when there's sub-optimal layout. Better to fix the layout then the power supplies might not need changing at all. But depending on the pcb construction, fixing the grounding might be too hard, in which case improving the supplies/opamps is the next best thing.

As regards rectifier mods - very cheap RC snubbers are the way to go. Perhaps soft-recovery diodes, but I'm not totally convinced.

The bleached sound in my experience is not primarily opamp related, assuming they're not using devices cheaper than 5532s (except in the special case of I/V opamp). Rather its more likely to be corrupted grounds by poor decoupling. It can be ameliorated by putting in certain more expensive opamps, but again that's a band-aid - the improvements I think won't be as marked as really fixing the noise issues.

So those things will help, just I can help thinking there are more cost-effective ways of getting the same, or potentially better results. There's also the psychology of mods - when you've paid $175 there's a certain expectation bias when listening to the result, and post-purchase rationalisation kicks in